Axolotls out on limb for future human hope

An axolotl’s ability to regrow limbs and repair brain and heart tissue could shed light on how humans might one day do the same, after Melbourne scientists discovered the key role played by macrophages, immune system cells, in the animal’s regenerative process.

Axolotls are known for their ability to regrow limbs.

James Godwin and his colleagues at the Australian Regenerative Medicine Institute (ARMI) have identified the critical role of macrophages in axolotl tissue regeneration, raising the hope of future treatments for human spinal cord and brain injuries, as well as heart and liver disease.

“We need to find out exactly how the macrophages are contributing to regeneration. Down the road, this could lead to therapies that tweak the human immune system into a more regenerative pathway,” James says.

Axolotls, a type of salamander, are known for their ability to regrow limbs and regenerate spinal cord, brain and heart tissue. The healed limb or tissue is completely functional and scar-free.

James and his team discovered that when they removed axolotls’ macrophages, the animals lost their ability to regenerate limbs and they formed scar tissue instead.

James also believes that studying the animal’s regenerative processes could lead to new treatments for several common conditions linked to fibrosis or scarring, such as heart and liver diseases.

Promotion of scar-free healing would also dramatically improve patient recovery after surgery.

James is an independent research fellow in Nadia Rosenthal’s ARMI laboratory at Monash University, and he has been instrumental in setting up a breeding colony of axolotls to study regeneration further.

“We need to know exactly what salamanders do, and how they do it so well, so we can reverse-engineer that capacity into human therapies.”